Immunocompromised patients including those who have undergone hematopoietic stem cell (HSCT) and solid organ (SOT) transplants are at markedly increased risk for severe disease caused by respiratory pathogens. These patients have greater susceptibility to a broader range of organisms and frequently present with more advanced disease. In addition, they often have higher organism burden and are infected with multiple pathogens either as primary infectious agents or as a secondary infectious complication. Moreover, because of an impaired host immunologic response to infectious agents, immune based diagnostic strategies such as serology can be unreliable. While molecular assays offer the advantage of improved sensitivity and specificity, most testing of respiratory samples is done by singleplex PCR that are performed by send-out specialty laboratories and take several days or more before results are available. The lack of rapid diagnostic testing for a wide range of respiratory pathogens often results in a delay in initiation of targeted anti-microbial therapies, which can result in increased morbidity and mortality. Indeed, transplant and immunocompromised patients provide a significant diagnostic challenge and a great unmet clinical need. The goal of this Phase I SBIR study is to test 300 respiratory samples from adult HSCT/SOT patients followed at Brigham &Women's Hospital/Dana-Farber Cancer Institute using a multiplex PCR (FilmArray RP) system that features the real-time capacity of detecting 22 respiratory pathogens within one hour. Specifically, we will compare the diagnostic performance of the FilmArray RP system to currently used CLIA approved clinical diagnostic assays for respiratory pathogens in transplant patients, both HSCT and SOT, sampled by nasopharyngeal aspirate (NPA) and by bronchoalveolar lavage (BAL). We anticipate that the results from this Phase I study will lead to an innovative Phase II study where a multiplex PCR pouch designed to detect an expanded panel of respiratory pathogens will be tested. The successful testing of the FilmArray RP system could ultimately lead to improved management of this immunocompromised patient population and potentially lead to an overall deceased cost in health care delivery. PUBLIC HEALTH RELEVANCE: Undiagnosed respiratory pathogens are a major problem for organ transplant patients because their immune systems are often not fully functional. Idaho Technology Incorporated has developed a diagnostic system (termed FilmArray) that can rapidly (<1 hour) detect a large number of respiratory pathogens with minimal operator effort. We will test the idea that FilmArray can aid in the diagnosis of respiratory symptoms in transplant patients and thus lead to improved treatment.